Speedo Gear & Drive Gear For 37's

[Pino2234]

My truck has 37s and 3.55s. I counted 16 tooth speedo gear in my NP208 transfer case. I am pretty sure I have to go down in speedo gear to 15 or 14 however they dont make ones that low.

Whats next?

According to my GPS when I'm going like 45mph my dash says like 40-42.

 

[Pino2234]

I calculated at This Place that I need an 8 tooth Drive Gear for my NP208 to work this all out.

Ok now where do I find one